Electric truck thermal management system based on secondary circuit

Abstract

The invention discloses an electric truck thermal management system based on a secondary circuit. The electric truck thermal management system based on the secondary loop comprises a first refrigerant loop formed by connecting a first compressor, a first condenser, a first control valve and a first evaporator in series and a second refrigerant loop formed by connecting a second compressor, a second condenser, a second control valve and a second evaporator in series. A heat exchange channel of the second condenser is connected with a controller, a motor, a third multi-way water valve, a motor radiator and an electric drive water pump in series to form an electric drive cooling liquid loop, one connector of the second multi-way water valve is connected with a battery cooling liquid loop through a first water inlet pipe, and the battery cooling liquid loop is communicated with a liquid inlet of a heat exchange channel of the second evaporator through a first water return pipe. And a liquid outlet of the heat exchange passage of the second evaporator is communicated to a pipeline connected between the liquid outlet of the cold air core body and the liquid inlet of the heat exchange passage of the first evaporator through a first pipe. The problem that in the prior art, the cooling capacity is poor is solved.

Description

Technical Field

[0001] This invention relates to the field of vehicle thermal management system technology, and in particular to a thermal management system for electric trucks based on a secondary loop. Background Technology

[0002] There is a Chinese invention patent with publication number CN119749172B, entitled "Secondary Circuit Thermal Management System and Electric Vehicle." It discloses a passenger compartment + battery cooling mode, in which the cooling capacity of the cooling air core and battery coolant plate is provided by the secondary circuit (refrigerant circuit). However, some large vehicles, such as electric trucks, have larger battery packs and require higher cooling capacity when operating in high-temperature summer environments. The existing technology, containing only one secondary circuit, is clearly insufficient to meet these requirements. Summary of the Invention

[0003] The purpose of this invention is to provide a thermal management system for electric trucks based on a secondary circuit, which has strong cooling capabilities and is particularly able to meet the needs of use in high-temperature environments or fast-charging scenarios.

[0004] To achieve the above-mentioned objectives, the electric truck thermal management system based on a secondary loop of the present invention adopts the following technical solution:

[0005] A thermal management system for electric trucks based on a secondary loop includes a refrigerant loop one consisting of a compressor one, a condenser one, a control valve one, and an evaporator one connected in series, and a refrigerant loop two consisting of a compressor two, a condenser two, a control valve two, and an evaporator two connected in series. The heat exchange path of the condenser one is connected in series with an air conditioning water pump two, a heater core, and a multi-way water valve one to form a heater loop. The multi-way water valve one is connected to an air conditioning radiator for dissipating heat from the condenser one. The heat exchange path of the evaporator one is connected in series with the air conditioning water pump one, the multi-way water valve one, and the control valve one. Valve 2 and the cold air core are connected in series to form a cold air circuit. The heat exchange passage of condenser 2 is connected in series with the controller, motor, multi-way water valve 3, motor radiator, and electric water pump to form an electric coolant circuit. One port of multi-way water valve 2 is connected to the battery coolant circuit through water inlet pipe 1. The battery coolant circuit is connected to the liquid inlet of the heat exchange passage of evaporator 2 through water return pipe 1. The liquid outlet of the heat exchange passage of evaporator 2 is connected to the pipeline connecting the liquid outlet of the cold air core and the liquid inlet of the heat exchange passage of evaporator 1 through pipe 1.

[0006] Preferably, one interface of the multi-way water valve three is connected to the return water pipe one through pipe two, and the pipe connecting the electric water pump and the motor radiator is connected to pipe one through pipe three.

[0007] Preferably, one port of the multi-port water valve is connected to the return water pipe via pipe four.

[0008] Preferably, the battery coolant circuit consists of a battery, an electric heater, and a battery water pump connected in series.

[0009] Preferably, the multi-way water valve is a three-way proportional valve, and the three ports of the multi-way water valve are respectively connected to the liquid outlet of the heat exchange passage of the evaporator, the liquid inlet of the heater core, and the liquid inlet of the air conditioner radiator.

[0010] Preferably, the multi-way water valve is a four-way proportional valve. Three of the ports of the multi-way water valve are respectively connected to the liquid outlet of the heat exchange passage of the evaporator, the liquid inlet of the heater core, and the liquid inlet of the air conditioner radiator. The other port of the multi-way water valve is connected to the battery coolant circuit through the water inlet pipe 2. The battery coolant circuit is connected to the heater circuit through the water return pipe 2.

[0011] Preferably, the refrigerant circuit one further includes an intermediate heat exchanger one and a liquid receiver one. The inlet of the low-pressure side passage of the intermediate heat exchanger one is connected to the outlet of the evaporation passage of the evaporator one. The outlet of the low-pressure side passage of the intermediate heat exchanger one is connected to the inlet of the compressor one. The liquid inlet of the high-pressure side passage of the intermediate heat exchanger one is connected to the outlet of the liquid receiver one. The liquid inlet of the liquid receiver one is connected to the outlet of the condensation passage of the condenser one. The liquid outlet of the high-pressure side passage of the intermediate heat exchanger one is connected to the control valve one.

[0012] Preferably, the refrigerant circuit two further includes an intermediate heat exchanger two and a liquid receiver two. The inlet of the low-pressure side passage of the intermediate heat exchanger two is connected to the outlet of the evaporation passage of the evaporator two. The outlet of the low-pressure side passage of the intermediate heat exchanger two is connected to the inlet of the compressor two. The liquid inlet of the high-pressure side passage of the intermediate heat exchanger two is connected to the outlet of the liquid receiver two. The liquid inlet of the liquid receiver two is connected to the outlet of the condensation passage of the condenser two. The liquid outlet of the high-pressure side passage of the intermediate heat exchanger two is connected to the control valve two.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0014] 1. Under normal operating conditions, the refrigerant circuit one provides cooling capacity to the cold air circuit and the battery coolant circuit. When the system cooling capacity requirement increases, the cooling capacity is increased through the refrigerant circuit two, so that the system can meet the usage requirements in high-temperature environments or fast charging scenarios.

[0015] 2. It is applicable to more scenarios, such as when the passenger cabin needs heating or the battery needs cooling. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0017] Figure 2 This is the working principle diagram for working condition one.

[0018] Figure 3 This is the working principle diagram for working condition two.

[0019] Figure 4 This is the working principle diagram for working condition three.

[0020] Figure 5 This is the working principle diagram for working condition four.

[0021] Figure 6 This is the working principle diagram for working condition five.

[0022] Figure 7 This is a schematic diagram illustrating the working principle of multi-temperature zone control required for operating condition five.

[0023] Figure 8 This is the working principle diagram for working condition six.

[0024] Figure 9 This is the working principle diagram for working condition seven.

[0025] Figure 10 This is the working principle diagram for working condition eight.

[0026] Figure 11 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0027] Figure 12 This is the working principle diagram for working condition nine.

[0028] Figure 13 This is the working principle diagram for working condition 10.

[0029] Figure 14 This is a schematic diagram illustrating the working principle when there is excessive residual heat in the motor under operating condition 10.

[0030] The components are as follows: 1. Compressor 1; 2. Condenser 1; 3. Liquid Receiver 1; 4. Intermediate Heat Exchanger 1; 5. Control Valve 1; 6. Evaporator 1; 7. Compressor 2; 8. Condenser 2; 9. Liquid Receiver 2; 10. Intermediate Heat Exchanger 2; 11. Control Valve 2; 12. Evaporator 2; 13. Air Conditioning Water Pump 2; 14. Heater Core; 15. Multi-way Water Valve 1; 16. Air Conditioning Radiator; 17. Air Conditioning Water Pump 1; 18. Multi-way Water Valve 2; 19. Cold Air Core; 20. Controller; 21. Motor; 22. Multi-way Water Valve 3; 23. Motor Radiator; 24. Electric Water Pump; 25. Inlet Pipe 1; 26. Battery; 27. Electric Heater; 28. Battery Water Pump; 29. ​​Return Pipe 1; 30. Pipe 1; 31. Pipe 2; 32. Pipe 3; 33. Pipe 4; 34. Inlet Pipe 2; 35. Return Pipe 2. Detailed Implementation

[0031] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.

[0032] Example 1, as Figure 1As shown, a thermal management system for an electric truck based on a secondary loop includes a refrigerant loop one consisting of a compressor-1, a condenser-2, a liquid receiver-3, an intermediate heat exchanger-4, a control valve-5, and an evaporator-6 connected in series, and a refrigerant loop two consisting of a compressor-2, a condenser-2, a liquid receiver-9, an intermediate heat exchanger-2 10, a control valve-2 11, and an evaporator-2 12 connected in series. The inlet of the low-pressure side passage of the intermediate heat exchanger-4 is connected to the outlet of the evaporation passage of the evaporator-6; the outlet of the low-pressure side passage of the intermediate heat exchanger-4 is connected to the inlet of the compressor-1; the outlet of the compressor-1 is connected to the inlet of the condensation passage of the condenser-2; and the liquid inlet of the high-pressure side passage of the intermediate heat exchanger-4 is connected to the outlet of the liquid receiver-3. The liquid inlet of liquid storage tank 3 is connected to the liquid outlet of the condensing passage of condenser 2. The liquid outlet of the high-pressure side passage of intermediate heat exchanger 4 is connected to the air inlet of the evaporating passage of evaporator 6 through control valve 5. The air inlet of the low-pressure side passage of intermediate heat exchanger 10 is connected to the air outlet of the evaporating passage of evaporator 22. The air outlet of the low-pressure side passage of intermediate heat exchanger 10 is connected to the air inlet of compressor 7. The air outlet of compressor 7 is connected to the air inlet of the condensing passage of condenser 8. The liquid inlet of the high-pressure side passage of intermediate heat exchanger 10 is connected to the liquid outlet of liquid storage tank 9. The liquid inlet of liquid storage tank 9 is connected to the liquid outlet of the condensing passage of condenser 8. The liquid outlet of the high-pressure side passage of intermediate heat exchanger 10 is connected to control valve 11. The air inlet of the evaporation passage of evaporator 12 is connected to the air inlet. Control valves 11 and 21 are both electronic expansion valves. The heat exchange passage of condenser 2 is connected in series with air conditioning water pump 13, heater core 14, and multi-way water valve 15 to form a heater circuit. Multi-way water valve 15 is a three-way proportional water valve. Port a of multi-way water valve 15 is connected to the liquid outlet of the heat exchange passage of condenser 2. Port c of multi-way water valve 15 is connected to the liquid inlet of heater core 14. The liquid outlet of heater core 14 is connected to the liquid inlet of air conditioning water pump 13. The liquid outlet of air conditioning water pump 13 is connected to the liquid inlet of the heat exchange passage of condenser 2. Port b of multi-way water valve 15 is connected to air conditioning radiator 16. The liquid inlet of air conditioning radiator 16 is connected to multi-way water valve 15. The b-port of valve 15 is connected. The outlet of the air conditioner radiator 16 is connected to the pipe between the inlet of the air conditioner water pump 13 and the outlet of the heater core 14. After exchanging heat with the air, the air conditioner radiator 16 dissipates heat to the condenser 2. The heat exchange path of the evaporator 6 is connected in series with the air conditioner water pump 17, the multi-way water valve 18, and the cold air core 19 to form a cold air circuit. The multi-way water valve 18 is a four-way proportional water valve. The a-port of the multi-way water valve 18 is connected to the outlet of the air conditioner water pump 17. The inlet of the air conditioner water pump 17 is connected to the outlet of the heat exchange path of the evaporator 6. The inlet of the heat exchange path of the evaporator 6 is connected to the outlet of the cold air core 19. The inlet of the cold air core 19 is connected to the c-port of the multi-way water valve 18.The heat exchange passage of condenser 2 8 is connected in series with controller 20, motor 21, multi-way water valve 3 22, motor radiator 23, and electric water pump 24 to form an electric coolant circuit. Multi-way water valve 3 22 is a three-way proportional water valve. Its a port is connected in series with motor 21 and controller 20, and then connects to the outlet of the heat exchange passage of condenser 2 8. Its c port is connected in series with motor radiator 23 and electric water pump 24, and then connects to the inlet of the heat exchange passage of condenser 2 8. The b port of multi-way water valve 2 18 is connected to the battery coolant circuit via inlet pipe 1 25. The battery coolant circuit consists of battery 26, electric heater 27, and battery water pump. Units 28 are connected in series. The inlet pipe 25 is connected to the pipe between the electric heater 27 and the battery water pump 28. The pipe between the battery 26 and the electric heater 27 is connected to the liquid inlet of the heat exchange passage of the evaporator 22 via the return water pipe 29. The liquid outlet of the heat exchange passage of the evaporator 22 is connected to the pipe connecting the liquid outlet of the cold air core 19 and the liquid inlet of the heat exchange passage of the evaporator 6 via pipe 30. The b-port of the multi-way water valve 22 is connected to the return water pipe 29 via pipe 21. The pipe connecting the electric water pump 24 and the motor radiator 23 is connected to pipe 30 via pipe 32. The d-port of the multi-way water valve 18 is connected to the return water pipe 29 via pipe 43.

[0033] The specific working process and principle of Embodiment 1 of the present invention include the following application scenarios:

[0034] Operating Condition 1: When the ambient temperature is below -20℃, the crew compartment is heated separately using an electric heater.

[0035] like Figure 2 As shown, under this operating condition, only ports a and c of multi-way water valve 15 are connected, only ports a and b of multi-way water valve 18 are connected, and only ports a and c of multi-way water valve 22 are connected. Air conditioning water pump 17 pumps coolant into the battery coolant circuit through inlet pipe 25. According to the law of conservation of flow, an equal amount of coolant, after being heated by electric heater 27, flows out of the battery coolant circuit. The outflowing coolant passes through return pipe 29, the heat exchange path of evaporator 2 12, pipe 30, and the heat exchange path of evaporator 6. The refrigerant circulates in the inlet pipe 25 and passes through the heat exchange passage of the evaporator 6. The refrigerant in the refrigerant circuit absorbs heat and completely vaporizes from a liquid state into a low-temperature, low-pressure gaseous refrigerant. The compressor 1 performs adiabatic compression on it, turning it into a high-temperature, high-pressure gaseous refrigerant. When the high-temperature, high-pressure gaseous refrigerant passes through the condensation passage of the condenser 2, the coolant in the heating circuit absorbs heat. Under the action of the air conditioning water pump 13, the coolant flows into the heating core 14 after absorbing heat to heat the passenger compartment.

[0036] Operating Condition 2: When the ambient temperature is below -20℃, the electric heater and waste heat from the motor are used to simultaneously heat the crew compartment and the battery.

[0037] like Figure 3 As shown, under this operating condition, only ports a and c of the multi-way water valve 15 are connected, only ports a and b of the multi-way water valve 18 are connected, and only ports a and b of the multi-way water valve 22 are connected. The coolant in the battery coolant circuit is heated by the electric heater 27 and, under the action of the battery water pump 28, self-circulates to heat the battery 26. At the same time, under the action of the air conditioning water pump 17, external coolant enters the battery coolant circuit through the inlet pipe 25. According to the law of conservation of flow, an equal amount of coolant is discharged from the battery coolant circuit through the return pipe 29. Under the action of the electric drive water pump 24, the coolant in the electric drive coolant circuit increases in temperature after passing through the controller 20 and the motor 21, and reacts with the electric motor. The coolant discharged from the pool coolant circuit is collected and discharged from the outlet of the heat exchange circuit of evaporator 2 12. Part of it returns to the electric water pump through pipe 3 32 to complete the circulation, and the other part enters the heat exchange passage of evaporator 1 6 through pipe 1 30. At this time, the refrigerant in refrigerant circuit 1 absorbs heat and completely vaporizes from liquid to low-temperature, low-pressure gaseous refrigerant. Compressor 1 performs adiabatic compression on it, turning it into high-temperature, high-pressure gaseous refrigerant. When the high-temperature, high-pressure gaseous refrigerant passes through the condensation passage of condenser 2, the coolant in the heating circuit absorbs heat. Under the action of air conditioning water pump 2 13, the coolant flows into the heating core 14 after absorbing heat to heat the passenger compartment.

[0038] Operating Condition 3: When the ambient temperature is between -20℃ and 20℃, the waste heat from the motor is used to heat the passenger compartment.

[0039] like Figure 4 As shown, under this operating condition, only ports a and c of multi-way water valve 15 are connected, only ports a and d of multi-way water valve 18 are connected, and only ports a and b of multi-way water valve 22 are connected. Under the action of electric water pump 24, the coolant in the electric coolant circuit increases in temperature after passing through controller 20 and motor 21, and enters the heat exchange circuit of evaporator 22 through return water pipe 29. Part of the coolant discharged from the outlet of the heat exchange circuit of evaporator 22 returns to electric water pump 24 through pipe 32 to complete the circulation, and the other part is discharged into the air. Under the action of the water pump 17, the refrigerant enters the heat exchange passage of the evaporator 6 through the pipe 30. At this time, the refrigerant in the refrigerant circuit 1 absorbs heat and completely vaporizes from liquid to low-temperature, low-pressure gaseous refrigerant. The compressor 1 performs adiabatic compression on it, making it into high-temperature, high-pressure gaseous refrigerant. When the high-temperature, high-pressure gaseous refrigerant passes through the condensation passage of the condenser 2, the coolant in the heating circuit absorbs heat. Under the action of the air conditioning water pump 13, the coolant flows into the heating core 14 after absorbing heat to heat the passenger compartment.

[0040] Operating Condition 4: When the ambient temperature is between -20℃ and 0℃, the air conditioning heat pump provides heating to the passenger compartment separately.

[0041] like Figure 5 As shown, under this operating condition, only ports a and c of multi-way water valve 15 are connected, only ports a and d of multi-way water valve 28 are connected, and ports a and b and ports a and c of multi-way water valve 32 are connected simultaneously. The coolant in the electric drive coolant circuit absorbs external heat through the motor radiator 23, and under the action of the electric drive water pump 24, part of the coolant returns to the motor radiator 23 through ports a and c of multi-way water valve 32 to complete the cycle and continuously absorb heat, while the other part of the coolant enters the heat exchange circuit of evaporator 22 through ports a and b of multi-way water valve 32. The coolant discharged from the outlet of the heat exchange circuit of evaporator 22 is... Part of the liquid returns to the electric water pump through pipe 32 to complete the circulation, while the other part enters the heat exchange passage of evaporator 6 through pipe 30 under the action of air conditioning water pump 17. At this time, the refrigerant in refrigerant circuit 1 absorbs heat and completely vaporizes from liquid to low-temperature, low-pressure gaseous refrigerant. Compressor 1 performs adiabatic compression on it, turning it into high-temperature, high-pressure gaseous refrigerant. When the high-temperature, high-pressure gaseous refrigerant passes through the condensation passage of condenser 2, the coolant in the heating circuit absorbs heat. Under the action of air conditioning water pump 2 13, the coolant flows into the heating core 14 after absorbing heat to heat the passenger compartment.

[0042] Operating Condition 5: Single compressor refrigeration of the crew cabin and battery

[0043] like Figure 6As shown, under this operating condition, only ports a and b of multi-way water valve 15 are connected; ports a and b, and ports a and c of multi-way water valve 18 are simultaneously connected; and only ports a and c of multi-way water valve 22 are connected. The refrigerant in refrigerant circuit 1 is transformed into a high-temperature, high-pressure gaseous state by compressor 1. This high-temperature, high-pressure gaseous refrigerant releases heat as it passes through the condensation path of condenser 2, condensing into liquid refrigerant. Under the action of air conditioning water pump 2 13, the coolant in the heat exchange path of condenser 2 flows to air conditioning radiator 16. The coolant in air conditioning radiator 16 cools down after exchanging heat with the outside environment and then flows back to the heat exchange path of condenser 2. This cycle continues to cool condenser 2. The high-temperature, high-pressure liquid refrigerant undergoes gas-liquid separation in the liquid storage tank 3. The pure liquid refrigerant enters control valve 5 and becomes a low-temperature, low-pressure gas-liquid mixed refrigerant. This low-temperature, low-pressure gas-liquid mixed refrigerant then enters the evaporator... The evaporation path of evaporator 6 absorbs heat. At this time, the coolant in the heat exchange path of evaporator 6 is cooled down. Under the action of air conditioning water pump 17 and battery water pump 28, part of the coolant flowing out of the outlet of the heat exchange path of evaporator 6 flows to the cold air core 19 through the a and c interfaces of multi-way water valve 28. The coolant flowing out of the outlet of cold air core 19 flows back to the evaporation path of evaporator 6. This cycle achieves the cooling of the passenger compartment. Another part of the coolant enters the battery coolant circuit through the a and b interfaces of multi-way water valve 28 and the inlet pipe 25. According to the law of conservation of flow, an equal amount of coolant is discharged from the battery coolant circuit through the return pipe 29, taking away the heat in the battery coolant circuit. The coolant entering the return pipe 29 flows back to the evaporation path of evaporator 6 through the evaporation path of evaporator 22 and pipe 30. This cycle achieves the cooling of battery 26.

[0044] Based on this operating condition, such as Figure 7 As shown, the a and c ports of the multi-way water valve 15 can also be connected, that is, the a and b ports and the a and c ports of the multi-way water valve 15 are connected, so that part of the coolant that has completed heat absorption in the heat exchange passage of the condenser 2 enters the heating core 14 through the a and c ports of the multi-way water valve 15. The ratio of the coolant to the heating air is adjusted by the temperature mode damper of the air conditioning unit, so as to achieve mixed air and different outlet air temperatures of different outlets of the air conditioning unit, thereby realizing multi-temperature zone control of the passenger cabin.

[0045] Operating Condition 6: Dual compressors refrigerate the crew cabin and batteries.

[0046] like Figure 8As shown, under this operating condition, only ports a and b of multi-way water valve 15 are connected; ports a and b, and ports a and c of multi-way water valve 18 are connected simultaneously; and only ports a and c of multi-way water valve 22 are connected. The refrigerant in refrigerant circuit 2 is transformed into a high-temperature, high-pressure gaseous state by compressor 27. This high-temperature, high-pressure gaseous refrigerant releases heat as it passes through the condensation passage of condenser 28, condensing into liquid refrigerant. Under the action of electric water pump 24, the coolant in the electric coolant circuit flows through motor radiator 23 and... External heat exchange cools the condenser 28, controller 20, and motor 21 continuously. Because the a and b ports of the multi-way water valve 32 are not connected, the coolant in pipe 32 is stagnant and does not participate in the flow. The coolant in the electric drive coolant circuit circulates independently. The high-temperature, high-pressure liquid refrigerant undergoes gas-liquid separation in the storage tank 29. The pure liquid refrigerant enters control valve 21 and becomes a low-temperature, low-pressure gas-liquid mixture, which then enters evaporator 212. The evaporation path absorbs heat. At this time, the coolant that brings heat from battery 26 in the heat exchange path of evaporator 212 cools down for the first time. Under the action of air conditioning water pump 17 and battery water pump 28, the coolant flowing out of the outlet of the heat exchange path of evaporator 212 enters the heat exchange path of evaporator 6 through pipe 30, and cools down again after exchanging heat with refrigerant circuit 1. A portion of the coolant with enhanced cooling force flows to the cold air core 19 through the a and c interfaces of multi-way water valve 218, and exits from the outlet of cold air core 19. The outflowing coolant flows back to the evaporation path of evaporator 6, thus circulating to cool the crew compartment. Another portion of the coolant enters the battery coolant circuit through the a and b ports of multi-way water valve 18 and the inlet pipe 25. According to the law of conservation of flow, an equal amount of coolant is discharged from the battery coolant circuit through the return pipe 29, continuously carrying away the heat in the battery coolant circuit. The coolant entering the return pipe 29 flows back to the heat exchange path of evaporator 12, thus circulating to cool the battery 26.

[0047] Based on this operating condition, the a and c ports of the multi-way water valve-15 can be connected, that is, the a and b ports and the a and c ports of the multi-way water valve-15 can be connected, so that part of the coolant that has completed heat absorption in the heat exchange passage of the condenser-2 enters the heating core 14 through the a and c ports of the multi-way water valve-15. The ratio of the coolant to the heating air is adjusted by the temperature mode damper of the air conditioning unit, so as to achieve mixed air and different outlet air temperatures of different outlets of the air conditioning unit, thereby realizing multi-temperature zone control of the passenger compartment.

[0048] Operating Condition 7: Passenger cabin heating, battery cooling

[0049] like Figure 9As shown, under this operating condition, only interfaces a and c of the multi-way water valve 15 are connected, only interfaces a and b of the multi-way water valve 18 are connected, and only interfaces a and c of the multi-way water valve 22 are connected. When the refrigerant in the refrigerant circuit 1 passes through the condenser 2, it exchanges heat with the coolant in the heating circuit and condenses into a liquid state, transferring heat to the heating circuit to heat the passenger compartment. When the refrigerant in the refrigerant circuit 1 enters the evaporation passage of the evaporator 6, it absorbs the heat of the coolant in the heat exchange passage of the evaporator 6 and evaporates into a gaseous state. Under the action of the air conditioning water pump 17, the coolant in the heat exchange passage of the evaporator 6 transfers the cooling capacity from the inlet pipe 25 to the battery coolant circuit. The coolant in the battery coolant circuit carries the heat of the battery and flows back to the heat exchange passage of the evaporator 6 through the return pipe 29, the heat exchange passage of the evaporator 2 12, and the pipe 30, thus circulating to achieve battery cooling.

[0050] Operating Condition 8: Passenger cabin heating, battery-enhanced cooling.

[0051] like Figure 10 As shown, under this operating condition, only ports a and c of multi-way water valve 15 are connected, only ports a and b of multi-way water valve 18 are connected, and ports a and c and ports a and b of multi-way water valve 22 are connected simultaneously. When the refrigerant in refrigerant circuit 1 passes through condenser 2, it exchanges heat with the coolant in the heating circuit and condenses into a liquid state, transferring heat to the heating circuit to heat the passenger compartment. When the refrigerant in refrigerant circuit 1 enters the evaporator 6 evaporation path, it absorbs heat from the coolant in the evaporator 6 heat exchange path and evaporates into a gaseous state. The coolant in the evaporator 6 heat exchange path, under the action of air conditioning water pump 17, transfers its cooling capacity through inlet pipe 25 to the battery coolant circuit. The coolant, carrying the heat from the battery, flows out through the return water pipe 29 and neutralizes with the coolant in the electric drive coolant circuit that has been mixed in through the a and b ports of the multi-way water valve 22. After neutralization, the coolant flows out from the outlet of the heat exchange passage of the evaporator 12, and a portion of it flows back into the electric drive coolant circuit through pipe 32. This means that a portion of the heat generated by the battery is dissipated into the air through the electric drive radiator 23, ensuring that the temperature of the coolant entering the heat exchange passage of the evaporator 6 through pipe 30 is relatively low. This, in turn, ensures that the coolant in the heat exchange passage of the evaporator 6 achieves an even lower temperature after exchanging heat with the refrigerant in the evaporation passage of the evaporator 6, thereby providing more cooling capacity to the battery coolant circuit and enhancing the cooling of the battery.

[0052] like Figure 11As shown, the difference between Embodiment 2 and Embodiment 1 is that the multi-way water valve 15 is a four-way proportional valve. The a port of the multi-way water valve 15 is connected to the liquid outlet of the heat exchange passage of the condenser 2, the c port of the multi-way water valve 15 is connected to the liquid inlet of the heater core 14, the b port of the multi-way water valve 15 is connected to the liquid inlet of the air conditioner radiator 16, and the d port of the multi-way water valve 15 is connected to the battery coolant circuit through the water inlet pipe 2 34. The battery coolant circuit is connected to the heater circuit through the water return pipe 2 35.

[0053] In addition to the above application scenarios, Example 2 can also be applied to the following application scenarios:

[0054] Operating Condition 9: When the ambient temperature is below -20°C, heat pumps and electric heaters are used to heat the crew compartment and batteries.

[0055] like Figure 12 As shown, under this operating condition, ports a and c, and ports a and d of multi-way water valve 15 are simultaneously connected; ports a and b, and ports a and d of multi-way water valve 18 are simultaneously connected; and only ports a and c of multi-way water valve 22 are connected. Electric heater 27 heats the coolant in the battery coolant circuit, and battery water pump 28 drives the coolant in the battery coolant circuit to circulate, heating the battery. A portion of the coolant pumped from the heat exchange passage of evaporator 6 by air conditioning water pump 17 returns directly to return water pipe 29 via ports a and d of multi-way water valve 18 through pipe 33. This reduces the amount of external coolant entering the battery coolant circuit via inlet pipe 25 through ports a and b of multi-way water valve 18. According to the law of conservation of flow, a smaller inflow into the battery coolant circuit results in a smaller outflow, thus saving heat in the battery coolant circuit and reducing cooling costs. After flowing out of the battery coolant circuit, the liquid introduces heat into the evaporator 6, serving as the heat source for the refrigerant circuit 1. The refrigerant in the refrigerant circuit 1 condenses and releases heat in the condenser 2, transferring the heat to the heating circuit. Under the action of the air conditioning water pump 13, part of the coolant in the heat exchange passage of the evaporator 6 absorbs heat and enters the heating core 14 through the a and c ports of the multi-way water valve 15 to heat the passenger compartment. The other part enters the battery coolant circuit through the a and d ports of the multi-way water valve 15 via the inlet pipe 34. An equal amount of coolant from the battery coolant circuit flows back to the heating circuit through the return pipe 35. Since the battery coolant circuit receives heat from the heating circuit and supplies less heat to the refrigerant circuit 1, the heating capacity of the system can be significantly improved or the power of the electric heater 27 can be indirectly reduced to achieve cost reduction under this condition.

[0056] Operating Condition 10: When the ambient temperature is below -20℃, the waste heat from the motor, heat pump, and electric heater are used to heat the crew compartment and battery.

[0057] like Figure 13As shown, under this operating condition, ports a and c, and ports a and d of multi-way water valve 15 are simultaneously connected; ports a and d of multi-way water valve 18 are only connected; and ports a and b of multi-way water valve 22 are only connected. Electric heater 27 heats the coolant in the battery coolant circuit, and battery water pump 28 drives the coolant in the battery coolant circuit to circulate, heating the battery. Under the action of electric pump 24, the coolant in the electric coolant circuit increases in temperature after passing through controller 20 and motor 21, and enters the heat exchange circuit of evaporator 12 through return pipe 29. Part of the coolant discharged from the outlet of the heat exchange circuit of evaporator 12 returns to electric pump 24 through pipe 32 to complete circulation, while the other part circulates in the air. Under the action of water pump 17, heat is introduced into the heat exchange passage of evaporator 6 through pipe 30, serving as the heat source for refrigerant circuit 1. The refrigerant in refrigerant circuit 1 condenses and releases heat in condenser 2, transferring the heat to the heating circuit. Under the action of air conditioning water pump 13, part of the coolant in the heat exchange passage of evaporator 6 absorbs heat and enters the heating core 14 through ports a and c of multi-way water valve 15, providing heating for the passenger compartment. The other part enters the battery coolant circuit through ports a and d of multi-way water valve 15 via inlet pipe 34. An equal amount of coolant from the battery coolant circuit flows back to the heating circuit through return pipe 35, thus replenishing the battery coolant circuit with heat from the heating circuit. It should be noted that, according to the law of conservation of flow, since inlet pipe 25 is disconnected, no coolant will flow from the battery coolant circuit to return pipe 29.

[0058] Based on this operating condition, if the motor has excessive residual heat, such as Figure 14 As shown, the a and c ports of the multi-way water valve 22 can also be connected to the motor radiator 23, allowing some of the waste heat from the motor 21 to be dissipated to the outside through the motor radiator 23. This configuration is also suitable when the outside temperature is slightly higher, as the motor radiator 23 absorbs heat from the outside and serves as the heat source needed for refrigerant evaporation in refrigerant circuit one.

[0059] This invention also has other applications, which will not be listed one by one, and can meet the needs of use in all scenarios.

[0060] The detailed description listed above is merely a specific description of feasible embodiments of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A thermal management system for electric trucks based on a secondary loop, characterized in that: The system includes a refrigerant circuit 1 consisting of a compressor 1, a condenser 1, a control valve 1, and an evaporator 1 connected in series, and a refrigerant circuit 2 consisting of a compressor 2, a condenser 2, a control valve 2, and an evaporator 2 connected in series. The heat exchange path of the condenser 1 forms a warm air circuit by connecting it in series with an air conditioning water pump 2, a warm air core, and a multi-way water valve 1. The multi-way water valve 1 is connected to an air conditioning radiator to dissipate heat from the condenser 1. The heat exchange path of the evaporator 1 forms a cold air circuit by connecting it in series with an air conditioning water pump 1, a multi-way water valve 2, and a cold air core. The heat exchange path of the condenser 2 forms an electric coolant circuit by connecting it in series with a controller, a motor, a multi-way water valve 3, a motor radiator, and an electric water pump. One port of the multi-way water valve 2 is connected to a battery coolant circuit via an inlet pipe 1. The battery coolant circuit is connected to the inlet of the heat exchange path of the evaporator 2 via a return pipe 1. The outlet of the heat exchange path of the evaporator 2 is connected to the pipeline connecting the outlet of the cold air core and the inlet of the heat exchange path of the evaporator 1 via a pipe 1.

2. The electric truck thermal management system based on a secondary loop according to claim 1, characterized in that: One of the interfaces of the multi-port water valve three is connected to the return water pipe one through pipe two, and the pipe connecting the electric water pump and the motor radiator is connected to pipe one through pipe three.

3. The electric truck thermal management system based on a secondary loop according to claim 2, characterized in that: One of the ports of the multi-port water valve is connected to the return water pipe through pipe four.

4. The electric truck thermal management system based on a secondary loop according to claim 3, characterized in that: The battery coolant circuit consists of a battery, an electric heater, and a battery water pump connected in series.

5. The electric truck thermal management system based on a secondary loop according to claim 4, characterized in that: The multi-port water valve is a three-way proportional valve, and its three ports are respectively connected to the liquid outlet of the heat exchange passage of the evaporator, the liquid inlet of the heater core, and the liquid inlet of the air conditioner radiator.

6. The electric truck thermal management system based on a secondary loop according to claim 4, characterized in that: The multi-way water valve is a four-way proportional valve. Three of its ports are connected to the liquid outlet of the heat exchange passage of the evaporator, the liquid inlet of the heater core, and the liquid inlet of the air conditioner radiator, respectively. The other port of the multi-way water valve is connected to the battery coolant circuit through the water inlet pipe 2. The battery coolant circuit is connected to the heater circuit through the water return pipe 2.

7. The electric truck thermal management system based on a secondary loop according to claim 1, characterized in that: The refrigerant circuit one also includes an intermediate heat exchanger one and a liquid receiver one. The inlet of the low-pressure side passage of the intermediate heat exchanger one is connected to the outlet of the evaporation passage of the evaporator one. The outlet of the low-pressure side passage of the intermediate heat exchanger one is connected to the inlet of the compressor one. The liquid inlet of the high-pressure side passage of the intermediate heat exchanger one is connected to the outlet of the liquid receiver one. The liquid inlet of the liquid receiver one is connected to the outlet of the condensation passage of the condenser one. The liquid outlet of the high-pressure side passage of the intermediate heat exchanger one is connected to the control valve one.

8. The electric truck thermal management system based on a secondary loop according to claim 1, characterized in that: The second refrigerant circuit also includes an intermediate heat exchanger and a liquid receiver. The inlet of the low-pressure side passage of the intermediate heat exchanger is connected to the outlet of the evaporation passage of the evaporator. The outlet of the low-pressure side passage of the intermediate heat exchanger is connected to the inlet of the compressor. The inlet of the high-pressure side passage of the intermediate heat exchanger is connected to the outlet of the liquid receiver. The inlet of the liquid receiver is connected to the outlet of the condensation passage of the condenser. The outlet of the high-pressure side passage of the intermediate heat exchanger is connected to the control valve.

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